1. Field of the Invention
The invention relates to an automotive milling machine, a method for discharging milled material, as well as a road or ground working unit.
2. Description of the Prior Art
With an automotive milling machine, it is known to discharge the milled material onto no less than one transport vehicle comprising a loading surface.
The milling machine comprises a controller for the travelling and milling operation, as well as a working drum for the milling of, for example, a road pavement. A transport conveyor device, for example, a transport conveyor device comprising no less than one transport conveyor, is present in front of or behind the working drum as seen in the direction of travel. The transport conveyor device comprises a discharge end at which the milled material is discharged onto the loading surface of the no less than one transport vehicle via a flight path in the form of a parabolic trajectory attributable to the conveying speed. The last or single transport conveyor of the transport conveyor device as seen in the direction of transport may be slewed sideways, relative to the longitudinal axis of the milling machine, under a specifiable slewing angle to the left or right and may be adjustable in height via a specifiable elevation angle. The conveying speed of the transport conveyor may also be adjustable.
In practical operation, problems arise in coordinating the milling machine with the transport vehicle.
With a forward-loading milling machine, for example, the milled material is discharged towards the front onto the transport vehicle driving ahead. The operator of the milling machine needs to signal to the vehicle driver of the transport vehicle as to when the transport vehicle is to continue moving forward and when it is to stop. This leads to problems because the operator basically needs to concentrate on the milling process and at the same time needs to avoid a collision with the transport vehicle driving ahead.
An additional problem lies in the fact that the operator of the milling machine also needs to deal with optimal loading of the loading surface by adjusting the slewing angle, elevation angle and conveying speed of the last or single transport conveyor of the transport conveyor device as seen in the direction of transport and is thus distracted from his actual task of carrying out the milling operation. A correction of the slewing angle may be required, for example, when altering the steering direction of the milling machine or for uniform loading of the loading surface.
In case of a rearward-loading milling machine, problems also arise in coordinating the milling machine with the transport vehicle especially as the transport vehicle needs to drive behind the milling machine in reverse travel. An even higher level of stress results for the operator of the milling machine as he needs to control the milling process in forward travel on the one hand, and needs to monitor loading of the transport vehicle behind the milling machine as seen in the direction of travel, needs to control the slewing angle, elevation angle and/or conveying speed of the transport conveyor device, and needs to communicate the necessary information for the stop-and-go operation to the vehicle driver on the other.
For reasons of design, the slewing angle range is limited mechanically to approx. ±30° with small milling machines and to approx. ±60° with large milling machines.
From DE 10 2012 215 013 A (US 2015/0218762), it is known to automate the discharging procedure where in particular also the slewing angle of the last or single transport conveyor of the transport conveyor device of the automotive milling machine as seen in the direction of transport is controllable automatically.
When controlling the slewing angle, the problem arises that, due to the many influencing factors such as, for example, cornering, different transport vehicles, distance to the transport vehicle, intermittent operation of the transport vehicle, the operator of the milling machine is quickly overwhelmed so that, in unfavourable circumstances, the milled material can also come down next to the loading surface of the transport vehicle. This is accompanied not only by the loss of the milled material but possibly also by extensive reworking in the event that the lost milled material comes to lie on a traffic lane extending next to the milled track from which it needs to be removed again.
Unintentional controlling errors may occur also in case of an automatic discharging procedure.